וירם משה את-ידו ויך את-הסלע במטהו פעמים ויצאו מים רבים ותשת העדה ובעירם
Moshe raised his hand and struck the rock twice with his staff. A lot of water came out and quenched the thirst of the congregation and their animals
The episode of Mei Merivah is one of the more famous episodes in the Torah, and one of the most difficult to understand. The whole story is only a few verses long, and describes the Jews’ thirst for water, Hashem commanding Moshe to speak to a rock, and Moshe’s sin of instead hitting this rock. The commentators struggle to understand what exactly he did wrong. Despite Moshe’s sin, the people got the water they requested. Hashem miraculously brought forth water from a rock, just because Moshe hit it. The verse says that a lot of water came out. This extra benefit would seem to be something positive, but perhaps there’s more to this miracle than meets the eye.
If one were to be asked: What’s a more impressive miracle? An abundance of food, which satiates an entire nation? Or a small amount of food, which despite its minute quantity, provides the same satiation as an abundance? Clearly the latter. This is how beracha, Hashem’s bountiful blessing, works. It’s praiseworthy through its quality, not its quantity. We know that Hashem promises us satiation if we follow His Torah. This satiation is the blessing that a small amount of food will go a long way.
The Jews for forty years sustained themselves by eating the heavenly bread known as munn. Our Sages tell us that it was the food that the Angels eat, or some say that every part of our body was nourished from it. Everyone received the same amount and was equally satisfied. When deserved, Hashem’s bounty knows no limits.
Therefore, if Moshe had spoken to the rock as he was commanded, the blessing that was in store for the Jews would have been of the highest quality. Just a little bit of water would have sustained them. More than this, their drinking would have been of a spiritual nature, like their consumption of the munn. It wouldn’t have been the same physical act of drinking which animals partake of.
However, since Moshe failed to follow Hashem’s instructions to speak to the rock, and he instead hit the rock, the beracha they received was lacking. Instead of being one of quality, it was one of quantity. They received a tremendous amount of water. Indeed, the first time they miraculously received water in the wilderness, it doesn’t say that they got “a lot of water”. Then, they were deserving of the higher level of blessing, that of quality. The verse also says that the water quenched the thirsts of the congregation and their animals. We see an equivalence between the two. What could have been a completely different act of drinking, for the Jews a spiritual one, and the animals a physical one, failed to materialize. We see from here even the subtle consequences of deviating from the command of Hashem.
 Based on Meshech Chochmah to Numbers 20:11
 Numbers loc. cit.
 Leviticus 26:5
 Rashi ad. loc.
 Yoma 78b
 Exodus 16:18
 Ibid 15:22-25. Also, in this episode, Hashem said that He would draw forth “water”, but not “a lot of water”. That was His initial intent
 Indeed, Hashem’s initial promise of water stated והשקית את העדה ואת בעירם. The ואת served to make a separation between the two types of drinking (see Bava Kamma 85b, and Rav Kupperman’s note § 4